I'd like to call this discussion to an end. As it was mentionned several times here and elsewhere, implementing a self-upgrade mechanism, be it silent or otherwise is for the moment not possible. It's high up there in terms of developpers visibility, meaning that developers know it's important but given the nature of our legacy code it requires a lot of efforts - or a lot of money. Unless someone here is willing to raise money and to write the full spec , this discussion is daydreaming :-) .
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